Process for producing coenzyme q10

ABSTRACT

The invention aims at providing a process for producing coenzyme Q 10  efficiently in microorganisms by utilizing a coenzyme Q 10  side chain synthesis gene derived from a fungal species belonging to the genus Rhodotorula.  
     The present invention relates to a DNA having a DNA sequence described under SEQ ID NO:1, 3 or 5 or derived from the above sequence by deletion, addition, insertion and/or substitution of one or several bases and encoding a protein having decaprenyl diphosphate synthase activity.

TECHNICAL FIELD

[0001] The present invention relates to a process for producing coenzyme Q₁₀, which is in use as a drug or the like. More particularly, it relates to a process for causing formation of coenzyme Q₁₀ by isolating a gene coding for a coenzyme Q₁₀ side chain synthase, which serves as a key enzyme in the biosynthesis of coenzyme Q₁₀, namely a decaprenyl diphosphate synthase, from a fungal species belonging to the genus Rhodotorula and introducing that gene into a host microorganism.

BACKGROUND ART

[0002] An industrial process for producing coenzyme Q₁₀, which is conventional in the art, comprises, for example, isolating coenzymes Q of plant origin, for example of tobacco origin, and adjusting the side chain length thereof by a synthetic method.

[0003] It is known that coenzyme Q₁₀ is produced in a wide variety of organisms, from microorganisms, such as bacteria and yeasts, to higher animals and plants. Thus, the process comprising cultivating a microorganism and extracting this substance from cells thereof can be regarded as one of the most efficient process for producing Q₁₀ and has actually been employed in commercial production thereof. However, the productivity of such processes can hardly be said to be good, since the yield is low and the procedure is complicated, for instance.

[0004] As for analogs (e.g. coenzyme Q₈) differing in chain length from coenzyme Q₁₀, not Q₁₀ itself, attempts have also been made to increase the production thereof by isolating genes involved in the biosynthesis thereof and amplifying the genes utilizing the recombinant DNA technology.

[0005] Coenzyme Q₁₀ is formed in vivo in a multistage process comprising complicated reactions in which a number of enzymes are involved. The route of biosynthesis thereof in prokaryotes partially differs from that in eukaryotes. Basically, however, each route comprises three fundamental steps, namely the step of synthesis of decaprenyl diphosphate, which is the source of the prenyl side chain of coenzyme Q₁₀, the step of synthesis of para-hydroxybenzoic acid, which is the source of the quinone ring, and the step of completion of coenzyme Q₁₀ through coupling of these two compounds and successive substituent conversions. Among these reactions, the reaction which determines the side chain length of coenzyme Q₁₀, namely the decaprenyl diphosphate synthase-involving reaction, which is said to be a rate-determining one in the whole biosynthetic reaction route, is considered to be the most important one.

[0006] Therefore, for efficient production of coenzyme Q₁₀, it is considered effective to isolate a decaprenyl diphosphate synthase gene, which is the key gene in the biosynthesis of coenzyme Q₁₀, and utilize the same for the purpose of increasing production. As for the gene source, fungi, in which coenzyme Q₁₀ is produced in relatively large amounts, are leading candidates.

[0007] So far, decaprenyl diphosphate synthase genes have been isolated from several microorganisms, such as Schizosa-charomyces pombe (JP-A-09-173076) and Gluconobacter suboxydans (JP-A-10-57072). However, the productivity of coenzyme Q₁₀ in these microorganisms cannot be said to be satisfactory, and the cultivation of these microorganisms and the separation/purification of coenzyme Q₁₀ therefrom have not been efficient. It has thus been desired that a microorganism-derived gene for that enzyme, which enables high level production of coenzyme Q₁₀, be isolated.

SUMMARY OF THE INVENTION

[0008] It is an object of the present invention to produce coenzyme Q₁₀ efficiently in microorganisms by isolating a coenzyme Q₁₀ side chain synthesis gene from a fungal species belonging to the genus Rhodotorula and utilizing the same to hereby solve the above-mentioned productivity problem.

[0009] For attaining the above object, the present inventors made investigations in an attempt to isolate a decaprenyl diphosphate synthase gene from fungi belonging to the genus Rhodotorula, in which coenzyme Q₁₀ is produced in relatively large amounts, and succeeded in isolating such gene. As a result of further investigations made by them to increase the expression level of that gene, they succeeded in improving the gene so that coenzyme Q₁₀ may be expressed more abundantly. These successes have now led to completion of the present invention.

[0010] Thus, the present invention provides

[0011] a DNA of the following (a), (b) or (c):

[0012] (a) a DNA whose base sequence is as described under SEQ ID NO:1;

[0013] (b) a DNA having a DNA sequence derived from the base sequence shown under SEQ ID NO:1 by deletion, addition, insertion and/or substitution of one or several bases and

[0014] encoding a protein having decaprenyl diphosphate synthase activity;

[0015] (c) a DNA capable of hybridizing with a DNA comprising the base sequence shown under SEQ ID NO:1 under stringent conditions and

[0016] encoding a protein having decaprenyl diphosphate synthase activity.

[0017] The invention further provides a DNA improved in its expression in prokaryotes, namely

[0018] a DNA of the following (d), (e) or (f):

[0019] (d) a DNA whose base sequence is as described under SEQ ID NO:3;

[0020] (e) a DNA having a DNA sequence derived from the base sequence shown under SEQ ID NO:3 by deletion, addition, insertion and/or substitution of one or several bases and

[0021] encoding a protein having decaprenyl diphosphate synthase activity;

[0022] (f) a DNA capable of hybridizing with a DNA comprising the base sequence shown under SEQ ID NO:3 under stringent conditions and

[0023] encoding a protein having decaprenyl diphosphate synthase activity.

[0024] The invention further provides a DNA improved in its expression in prokaryotes, namely

[0025] a DNA of the following (k), (1) or (m):

[0026] (k) a DNA whose base sequence is as described under SEQ ID NO:5;

[0027] (l) a DNA having a DNA sequence derived from the base sequence shown under SEQ ID NO:5 by deletion, addition, insertion and/or substitution of one or several bases and

[0028] encoding a protein having decaprenyl diphosphate synthase activity;

[0029] (m) a DNA capable of hybridizing with a DNA comprising the base sequence shown under SEQ ID NO:5 under stringent conditions and

[0030] encoding a protein having decaprenyl diphosphate synthase activity.

[0031] The invention further provides

[0032] a protein of the following (g) or (h):

[0033] (g) a protein whose amino acid sequence is as described under SEQ ID NO:2;

[0034] (h) a protein having an amino acid sequence derived from the amino acid sequence shown under SEQ ID NO:2 by deletion, addition, insertion and/or substitution of one or several amino acid residues and having decaprenyl diphosphate synthase activity.

[0035] The invention further provides

[0036] a protein of the following (i) or (j):

[0037] (i) a protein whose amino acid sequence is as described under SEQ ID NO:4;

[0038] (j) a protein having an amino acid sequence derived from the amino acid sequence shown under SEQ ID NO:4 by deletion, addition, insertion and/or substitution of one or several amino acid residues and having decaprenyl diphosphate synthase activity.

[0039] The invention further provides

[0040] a protein of the following (n) or (o):

[0041] (n) a protein whose amino acid sequence is as described under SEQ ID NO:6;

[0042] (o) a protein having an amino acid sequence derived from the amino acid sequence shown under SEQ ID NO:6 by deletion, addition, insertion and/or substitution of one or several amino acid residues and having decaprenyl diphosphate synthase activity.

[0043] The invention further provides

[0044] DNAs respectively encoding the above proteins (g) to

[0045] The invention further provides

[0046] expression vectors with the above DNAs inserted into vectors.

[0047] The invention further provides

[0048] transformants resulting from transformation of host microorganisms with the respective DNAs mentioned above or with the expression vectors mentioned above.

[0049] The invention further provides

[0050] a DNA encoding the protein (n) or (o).

[0051] The invention further provides

[0052] expression vectors with the above DNA inserted into vectors.

[0053] The invention further provides

[0054] transformants resulting from transformation of host microorganisms with the respective DNAs mentioned above or with the expression vectors mentioned above.

[0055] The invention still further provides

[0056] a process for producing coenzyme Q₁₀,

[0057] which comprises cultivating any of the above-mentioned transformants in a medium and recovering coenzyme Q₁₀ thus formed and accumulated in the medium.

DETAILED DISCLOSURE OF THE INVENTION

[0058] In the following, the present invention is described in detail.

[0059] The present inventors made investigations to isolate a gene encoding the enzyme in question from fungi belonging to the genus Rhodotorula, in which coenzyme Q₁₀ is produced in relatively large amounts, and, as a result, succeeded in obtaining a fragment of the gene by the PCR method.

[0060] The sequence of a known gene encoding a decaprenyl diphosphate synthase was compared with that of a known gene encoding a polyprenyl diphosphate synthase which is an analogue with different chain length of the enzyme in question and a long prenyl chain synthase of coenzyme Q, to the decaprenyl diphosphate synthase, and various PCR primers were synthesized for regions showing high homology therebetween. PCR conditions were studied for various combinations of these primers and, as a result, it was revealed, by gene base sequence analysis, that when 40 PCR cycles, each comprising 94° C., 1 minute→43° C., 2 minutes→72° C., 2 minutes, are carried out after 3 minutes of heat treatment at 94° C., using the primers DPS-1 (5′-AAGGATCCTNYTNCAYGAYGAYGT-3′) and DPS-1 1AS (5′-ARYTGNADRAAYTCNCC-3′) (in these sequences, R representing A or G, Y representing C or T, and N representing G, A, T or C), a fragment, about 220 bp in size, of the enzyme gene in question is amplified from the chromosomal gene of Rhodotorula minuta IFO 0387, which is a fungal species belonging to the genus Rhodotorula.

[0061] For obtaining the enzyme gene in its full length, the chromosomal gene of Rhodotorula minuta IFO 0387 was cleaved with the restriction enzyme EcoRI, and the cleavage products were inserted into a λ phage vector to construct a recombinant phage library. The resulting plaques were transferred to a nylon membrane, and plaque hybridization was carried out using the PCR fragment in a labeled form, whereby a clone having the decaprenyl diphosphate synthase gene in its full length could be obtained.

[0062] The base sequence of the decaprenyl diphosphate synthase gene contained in the clone obtained was determined, whereupon it was revealed that it has the sequence shown under SEQ ID NO:1 in the sequence listing. In the amino acid sequence (amino acid sequence described under SEQ ID NO:2 in the sequence listing) predicted from this base sequence, there was found a sequence characteristic of decaprenyl diphosphate synthase.

[0063] Since, in eukaryotes, the decaprenyl diphosphate synthase gene is expressed and functions in the mitochondria, it is supposed that, in the sequence on the amino acid terminal side of this gene sequence, there be a sequence allowing localization thereof in the mitochondria. Therefore, the inventors considered that, for more effective functioning of this gene in prokaryotes, it be necessary to specify and eliminate that or those sequences which is or are not essential in prokaryotes. As a result of studies on the amino acid terminal side sequence of that gene sequence, it has become possible to produce coenzyme Q₁₀ in significant amounts by using the gene specified under SEQ ID NO:3. The amino acid sequence deducible from the DNA sequence shown under SEQ ID NO:3 is described under SEQ ID NO:4 in the sequence listing. As a result of further studies on the amino acid terminal side sequence, it has become possible to produce coenzyme Q₁₀ in significant amounts by using the gene specified under SEQ ID NO:5. The amino acid sequence deducible from the DNA sequence shown under SEQ ID NO:5 is described under SEQ ID NO:6 in the sequence listing.

[0064] The DNA of the present invention may be a DNA whose base sequence is as described under SEQ ID NO:1 or SEQ ID NO:3, or a DNA having a base sequence derived from the base sequence shown under SEQ ID NO:1 or SEQ ID NO:3 by deletion, addition, insertion and/or substitution of one or several bases and encoding a protein having decaprenyl diphosphate synthase activity, or a DNA capable of hybridizing with a DNA comprising the base sequence shown under SEQ ID NO:1 or SEQ ID NO:3 under stringent conditions and encoding a protein having decaprenyl diphosphate synthase activity. A number of amino acids each may be encoded by one or more codons (genetic code degeneracy), so that a number of DNAs other than the DNA having the base sequence shown under SEQ ID NO:1 or SEQ ID NO:3 can encode the protein having the amino acid sequence shown under SEQ ID NO:2 or SEQ ID NO:4. Therefore, the DNA of the invention includes such DNAs en-coding the protein having the amino acid sequence shown under SEQ ID NO:2 or SEQ ID NO:4 as well.

[0065] The DNA of the present invention may be a DNA whose base sequence is as described under SEQ ID NO:5, or a DNA having a base sequence derived from the base sequence shown under SEQ ID NO:5 by deletion, addition, insertion and/or substitution of one or several bases and encoding a protein having decaprenyl diphosphate synthase activity, or a DNA capable of hybridizing with a DNA comprising the base sequence shown under SEQ ID NO:5 under stringent conditions and encoding a protein having decaprenyl diphosphate synthase activity. A number of amino acids each may be encoded by one or more codons (genetic code degeneracy), so that a number of DNAs other than the DNA having the base sequence shown under SEQ ID NO:5 can encode the protein having the amino acid sequence shown under SEQ ID NO:6. Therefore, the DNA of the invention includes such DNAs encoding the protein having the amino acid sequence shown under SEQ ID NO:6 as well.

[0066] The expression “base sequence derived by deletion, addition, insertion and/or substitution of one or several bases” as used herein means a base sequence resulting from deletion, addition, insertion and/or substitution of such a number of bases as can be deleted, added, inserted and/or substituted according to the methods well known to those skilled in the art, for example those described in Supplemental issue, Tanpakushitsu, Kakusan, Koso (Protein, Nucleic Acid and Enzyme), PCR Method for Gene Amplification, TAKKAJ, 35 (17), 2951-3178 (1990) or Henry A. Erlich (ed.), translated into Japanese under the supervision of Ikunoshin Kato: PCR Technology (1990).

[0067] The expression “DNA capable of hybridizing with a DNA comprising the base sequence shown under SEQ ID NO:1 (or SEQ ID NO:3 or SEQ ID NO:5) under stringent conditions” means a DNA obtainable by utilizing the technique of colony hybridization, plaque hybridization or southern hybridization, among others, using a DNA comprising the base sequence shown under SEQ ID NO:1 (or SEQ ID NO:3 or SEQ ID NO:5) as a probe. Those skilled in the art would be able to readily obtain the desired DNA by carrying out such hybridization according to the method described in Molecular Cloning, 2nd edition (Cold Spring Harbor Laboratry Press, 1989).

[0068] The expression “protein having decaprenyl diphosphate synthase activity” means a protein capable of synthesizing decaprenyl diphosphate in a yield of not less than 10%, preferably not less than 40%, more preferably not less than 60%, still more preferably not less than 80%, as compared with the case where a protein having the amino acid sequence shown under SEQ ID NO:2, SEQ ID NO:4 or SEQ ID NO:6. Such capacity can be measured by reacting FPP (farnesyl diphosphate) with ¹⁴C-IPP (radiolabeled isopentenyl diphosphate) in the presence of the enzyme in question, hydrolyzing the resulting ¹⁴C-DPP (decaprenyl diphosphate) with phosphatase and, after separation by TLC, determining the incorporation in each spot for each chain length (Okada et al., Eur. J. Biochem., 255, 52-59).

[0069] The protein of the invention may be a protein whose amino acid sequence is as described under SEQ ID NO:2, SEQ ID NO:4 or SEQ ID NO:6, or a protein having an amino acid sequence derived from the amino acid sequence shown under SEQ ID NO:2, SEQ ID NO:4 or SEQ ID NO:6 by deletion, addition, insertion and/or substitution of one or several amino acid residues and having decaprenyl diphosphate synthase activity. “Such an amino acid sequence derived by deletion, addition, insertion and/or substitution of one or several amino acid residues” can be obtained by deleting, adding, inserting and/or substituting an amino acid residue or residues by site-specific mutagenesis or any other methods well known in the art. Such methods are specifically described, for example, in Nucleic Acid Res., 10, 6487 (1982) and Methods in Enzymology, 100, 448 (1983).

[0070] For causing expression of the decaprenyl diphosphate synthase gene, it is necessary to connect that gene to a site downstream of an appropriate promoter. It is possible to construct an expression vector, for example, by excising a DNA fragment containing the gene using a restriction enzyme or amplifying an enzyme-encoding gene portion alone by PCR and then inserting the fragment or amplification product into a promoter-containing vector.

[0071] In the practice of the invention, the vector in which a DNA encoding a protein having decaprenyl diphosphate synthase activity is to be inserted to give an expression vector is not particularly restricted but may be one derived from an Escherichia coli-derived plasmid with an appropriate promoter inserted therein. The Escherichia coli-derived plasmid includes, among others, pBR322, pBR325, pUC19, and pUC119, and the promoter includes, among others, the T7 promoter, trp promoter, tac promoter, lac promoter, and λPL promoter. In the practice of the invention, pGEX-2T, PGEX-3T, pGEX-3X (the three being products of Pharmacia), pBluescriptII, pUC19, pUC18 (product of Toyobo Co., Ltd.), pMALC2, pET-3T, pUCNT (described in WO 94/03613) and the like may also be used as vectors for expression. Among these, PUCNT is judiciously used. In specific examples, a decaprenyl diphosphate synthase gene expression vector, pNTRm2, can be constructed by inserting a DNA comprising the base sequence shown under SEQ ID NO:1 into the vector for expression pUCNT, and an expression vector, pNTRm6, can be constructed by inserting a DNA comprising the base sequence shown under SEQ ID NO:3 into PUCNT. An expression vector, pUCRm3, can be constructed when a DNA comprising the base sequence shown under SEQ ID NO:5 is inserted into the vector for expression pUC18.

[0072] And, by introducing the above enzyme gene expression vector into an appropriate microorganism, it becomes possible to utilize the microorganism for the production of coenzyme Q₁₀. The host microorganism is not particularly restricted but Escherichia coli is judiciously used. The Escherichia coli strain is not particularly restricted but includes XL1-Blue, BL-21, JM109, NM522, DH5α, HB101, DH5, and pUC18, among others. Among these, Escherichia coli HB101 and pUC18 are judiciously used. For example, when the decaprenyl diphosphate synthase gene expression vector pNTRm2, pNTRm6 or pUCRm3 is introduced into Escherichia coli, this can be transformed so that coenzyme Q₁₀, which Escherichia coli originally does not produce, can be produced in significant amounts. The Escherichia coli strain with pNTRm2 introduced therein has been deposited, under the Budapest Treaty, with the National Institute of Advanced Industrial Science and Technology International Patent Organism Depositary (Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki, Japan) under the designation E. coli HB101(pNTRm2) FERM BP-15 7333, the Escherichia coli strain with pNTRm6 introduced therein under E. coli HB101(pNTRm6) FERM BP-7332, and the Escherichia coli strain with pUCRm3 under E. coli DH5α (pUCRm3) FERM BP-7638.

[0073] The gene of the invention may be used singly, or may be introduced into a microorganism together with another gene or other genes involved in the biosynthesis of coenzyme Q₁₀ for expression thereof. In the latter case, better results can be expected.

[0074] Coenzyme Q₁₀ can be produced by cultivating the transformant obtained in the invention in a medium in the conventional manner and recovering coenzyme Q₁₀ from the cultivation product. In cases where the host microorganism is Escherichia coli, LB medium, or M9 medium containing glucose and casamino acids can be used as the medium. For better promoter functioning, such an agent as isopropylthiogalactoside or indolyl-3-acrylic acid, for instance, may be added to the medium. The cultivation is carried out, for example, at 37° C. for 17 to 24 hours, if necessary with aeration and/or agitation. In the practice of the invention, the product coenzyme Q₁₀ obtained may be purified or used in the form of a crude product according to the selection duly made depending on the intended use thereof. Coenzyme Q₁₀ can be isolated from the ultivation product by an appropriate combination of per se known methods of separation and/or purification. The per se known methods of separation and/or purification include salting out, solvent precipitation and other methods utilizing the difference in solubility, dialysis, ultrafiltration, gel filtration, (SDS-)polyacrylamide gel electrophoresis and other methods mainly utilizing the difference in molecular weight, ion exchange chromatography and other methods utilizing the difference in charge, affinity chromatography and other methods utilizing specific affinity, reversed phase high-performance liquid chromatography and other methods utilizing the difference in hydrophobicity, isoelectric focusing and other methods utilizing the difference in isoelectric point, among others.

[0075] The field of utilization of coenzyme Q₁₀ obtained in the present invention is not particularly restricted but it may be judiciously used as a drug, among others.

BRIEF DESCRIPTION OF THE DRAWINGS

[0076]FIG. 1 is a restriction enzyme map of the expression vector pNTRm2.

[0077]FIG. 2 is a restriction enzyme map of the expression vector pNTRm6.

[0078]FIG. 3 shows HPLC analysis charts for the host and transformant products.

[0079]FIG. 4 is a restriction enzyme map of the expression vector pUCRm3.

[0080]FIG. 5 shows HPLC analysis charts for the products in the host for the expression vector pUCRm3 and in the transformant.

BEST MODES FOR CARRYING OUT THE INVENTION

[0081] The following examples illustrate the present invention in more detail. These examples are, however, by no means limitative of the scope of the invention.

EXAMPLE 1

[0082] The chromosomal DNA of Rhodotorula minuta IFO 0387 was prepared by the method of C. S. Hoffman et al. (Gene, 57 (1987), 267-272). Based on the homology with the known long-chain prenyl diphosphate synthase gene, primers for use in PCR, namely DPS-1 (5′-AAGGATCCTNYTNCAYGAYGAYGT-3′) and DPS-1 1AS (5′-ARYTGNADRAAYTCNCC-3′), were designed. In these sequences, R represents A or G, Y represents C or T, and N represents G, A, T or C. Using these, a PCR cycle of 94° C., 1 minute→43° C., 2 minutes→72° C., 2 minutes, were repeated 40 times after 3 minutes of heat treatment at 94° C. (ExTaq, product of Takara, being used as the enzyme), followed by 1.2% agarose gel electrophoresis.

[0083] The thus-obtained fragment, about 220 bp in size, was purified by excising the corresponding gel portion from the gel and then treating with a DNA extraction kit (Sephaglas (trademark) BrandPrep Kit, product of Amersham Pharmacia Biotech), and the purified fragment was cloned into a vector for expression in Escherichia coli using a PCR product direct cloning kit (pT7 BlueT-Vector Kit, product of NOVAGEN) to give pT7-RmDPS. The DNA base sequence was determined by carrying out the reaction on a DNA sequencer (model 377, product of PerkinElmer) using a DNA sequencing kit (product of PerkinElmer, ABI PRISM (trademark) BigDye (trademark) Terminator Cycle Sequence Ready Reaction Kit with AmptiTaq (registered trademark) DNA polymerase, FS) and according to the manual attached thereto. As a result, a sequence covering the 823rd to 1029th bases of the base sequence shown under SEQ ID NO:1 in the sequence listing was obtained. The sequence “GDFLLARA”, which is a characteristic region of the long-chain prenyl chain-containing prenyl diphosphate synthase, could be found in the sequence translated from the base sequence determined in the above manner. It was therefore estimated that the sequence obtained be part of the decaprenyl diphosphate synthase gene.

EXAMPLE 2

[0084] Using 0.03 μg of the pT7-RmDPS vector DNA having the 220 bp DNA fragment supposed to be part of the decaprenyl diphosphate synthase gene of Rhodotorula minuta IFO 0387 and using the PCR primers Rm-1S (having the sequence 5′-GCCATGAGGAGAGCACAAGCG-3′) and Rm-2AS (having the sequence 5′-CACGGAGGCTACTAGCTCGAC-3′), PCR (94° C., 3 minutes→(94° C., 30 seconds→55° C., 30 seconds→72° C., 1 minute)×25 cycles→72° C., 5 minutes→4° C.) was carried out, followed by 1.2% agarose (product of Takara Shuzo Co., Ltd.) gel electrophoresis. After excision of the corresponding portion from the gel, a fragment, about 145 bp in size, was purified using a DNA extraction kit (Sephaglas (trademark) BrandPrep Kit, product of Amersham Pharmacia Biotech). About 100 ng of this DNA fragment was subjected to chemiluminescence labeling using an ECL direct nucleic acid labeling system (product of Amersham Pharmacia Biotech).

EXAMPLE 3

[0085] The chromosomal DNA of Rhodotorula minuta IFO 0387 was cleaved with the restriction enzyme EcoRI, followed by 0.8% agarose gel electrophoresis. The gel was denatured with an alkali (0.5 M NaOH, 1.5 M NaCl) and then neutralized (0.5 M Tris-HCl (pH 7.5), 1.5 M NaCl), a Hibond N+ filter (product of Amersham) was laid on the gel, and southern transfer was effected overnight using 20×SSC. The filter was dried and baked at 80° C. for 2 hours and, thereafter, southern hybridization and detection were carried out using an ECL direct nucleic acid labeling/detection system (product of Amersham Pharmacia Biotech). Thus, using a Gold hybridization solution (product of Amersham Pharmacia Biotech), prehybridization was carried out at 42° C. for 1 hour.

[0086] The chemiluminescence-labeled probe was heated at 95° C. for 5 minutes, then quenched in ice, and added to the prehybridization for the prehydridized filter, and hybridization was carried out at 42° C. for 22 hours. This filter was washed with two portions of a 0.5×SSC solution containing 6 M urea and 0.4% SDS at 42° C. for 20 minutes (for each portion) and then with two portions of a 2×SSC solution at room temperature for 5 minutes (for each portion). This filter was immersed in an enhanced chemiluminescence reagent (product of Amersham Pharmacia Biotech) and brought into close contact with an X ray film for exposure thereof, and black bands resulting from exposure were detected. As a result, strong hybridization with a fragment, about 5.5 kbp in size, resulting from the cleavage with the restriction enzyme EcoRI was detected.

EXAMPLE 4

[0087] The chromosomal DNA of Rhodotorula minuta IFO 0387 was cleaved with the restriction enzyme EcoRI, followed by 0.8% agarose gel electrophoresis. A DNA fragment for use in cloning was prepared by excising the gel portion containing a DNA fragment in the vicinity of about 5.5 kbp in size and purifying the fragment. Using a λ-ZAPII phage kit (product of Stratagene), this DNA fragment was inserted into the phage at its EcoRI site, followed by packaging using an in vitro packaging kit (product of Amersham). Escherichia coli XL1-Blue MRF′ was infected with the phage and layered onto an NZY plate medium (5 g/L NaCl, 2 g/L MgSO₄.7H₂O, 5 g/L yeast extract, 10 g/L NZ amine, 18 g/L agar, pH 7.5), together with an NZY soft agar medium (same as the NZY plate medium except for the content of agar, which was 8 g/L), for plaque formation. The plaques were transferred onto a Hibond N+ filter (product of Amersham), denatured with an alkali (0.5 M NaOH, 1.5 M NaCl), neutralized (0.5 M Tris-HCl (pH 7.5), 1.5 M NaCl), dried, and baked at 80° C. for 2 hours.

[0088] Using 6 filters after baking as prepared in the above manner, prehybridization and hybridization using the chemiluminescence-labeled probe were carried out in the same manner as in Example 3, and the filters were washed. After drying, the filters were brought into close contact with an X ray film for exposure of the same, and the phage plaques corresponding to black spots resulting from exposure were isolated. Escherichia coli was infected with the phages of the thus-isolated plaques in the same manner as mentioned above for plaque formation. The plaques obtained were transferred onto a filter and again subjected to hybridization for confirmation. Seven phage strains could be selected.

[0089]Escherichia coli SOLR in the λ-ZAPII phage kit (product of Stratagene) was infected with each of those phages in a suspension form, together with the helper phage, and a phagemid was prepared in vitro. The above phagemid contained an insert fragment of about 5.5 kbp and, when PCR was carried out using the primers Rm-1S and Rm-2AS, the 145 bp DNA fragment could be detected. The DNA base sequence was determined by carrying out the reactions on a DNA sequencer (model 377, product of PerkinElmer, Inc.) using the internal primers Rm-1S and Rm-2AS and using a DNA sequencing kit (product of PerkinElmer, Inc., ABI PRISM (trademark) BigDye (trademark) Terminator Cycle Sequence Ready Reaction Kit with AmptiTaq (registered trademark) DNA polymerase, FS) according to the manual attached thereto. As a result of repeated sequencing using primers prepared based on the sequence revealed by preceding sequencing, the whole sequence of the decaprenyl diphosphate synthase gene of Rhodotorula minuta IFO 0387 could be revealed. Thus, the base sequence of a DNA of about 1.6 kbp was determined. The results are shown under SEQ ID NO:1 in the sequence listing. The amino acid sequence deduced from this DNA sequence is shown under SEQ ID NO:2.

EXAMPLE 5

[0090] For excising the decaprenyl diphosphate synthase-encoding gene portion from the phagemid DNA prepared, PCR was carried out in the same manner as in Example 2 using two synthetic DNA primers designated RM-1 (having the sequence 5′-ATCATATGATGCACCGACAAGCT-3′) and Rm-CE2 (having the sequence 5′-AAGAATTCCTACTTTGTTCGGTTGAGCACAG-3′). The amplification product was cleaved with the restriction enzymes NdeI and EcoRI, and the cleavage product was inserted into a vector for expression, PUCNT (described in WO 94/03613) to give a decaprenyl diphosphate synthase gene expression vector, pNTRm2. The restriction enzyme map of the thus-obtained expression vector pNTRm2 is shown in FIG. 1. The symbol DPS stands for the coding region of the decaprenyl diphosphate synthase gene.

EXAMPLE 6

[0091] The thus-constructed decaprenyl diphosphate synthase gene expression vector pNTRm2 was introduced into Escherichia coli HB101, the microorganisms were shake-cultured overnight in 10 mL of LB medium at 37° C., and cells were harvested by centrifugation (3,000 revolutions, 20 minutes).

[0092] The cells were suspended in 1 mL of a 3% aqueous solution of sulfuric acid and, after 30 minutes of heat treatment at 120° C., 2 mL of a 14% aqueous solution of sodium hydroxide was added, followed by further 15 minutes of heat treatment at 120° C. To the thus-treated suspension was added 3 mL of hexane-isopropanol (10:2) for effecting extraction. After centrifugation, 1.5 mL of the organic solvent layer was separated, and the solvent was evaporated to dryness under reduced pressure conditions. The residue was dissolved in 200 μl of ethanol, and 20 μl of the solution was analyzed by high-performance liquid chromatography (using LC-10A, product of Shimadzu Corp.). For separation, a reversed phase column (YMC-pack ODS-A, 250×4.6 mm, S-5 μm, 120A) was used, together with ethanol-methanol (2:1) as the mobile phase solvent. The coenzyme Q₁₀ formed was detected based on the absorbance at the wavelength 275 nm. The results are shown in FIG. 2. As shown in FIG. 2, it was revealed that, upon introduction of the decaprenyl diphosphate synthase gene for expression of Q₁₀, the transformant Escherichia coli strain was now possible to produce coenzyme Q₁₀, which is originally not produced in Escherichia coli.

[0093] The thus-obtained recombinant Escherichia coli HB101(pNTRm2) has been deposited, under the Budapest Treaty, with the National Institute of Advanced Industrial Science and Technology International Patent Organism Depositary (Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki, Japan) as of Oct. 19, 2000 (deposition/accession No. FERM BP-7333).

EXAMPLE 7

[0094] For eliminating the mitochondrial transitional sequence characteristic of eukaryotes from the sequence under SEQ ID NO:1 in order to attain abundant expression in prokaryotes, PCR was carried out in the same manner as in Example 2 using two synthetic DNA primers designated Rm-4 (having the sequence 5′-ATCATATGAATATTCGACCCACTCCAACT-3′) and Rm-CE2 (having the sequence 5′-AAGAATTCCTACTTTGTTCGGTTGAGCACAG-3′). The thus-amplified 1.3 kbp fragment was cleaved with the restriction enzymes NdeI and NheI, and the thus-prepared fragment, about 600 bp in size, was recombined to the major fragment of pNTRm2 as obtained by digestion with the restriction enzymes NdeI and NheI to construct pNTRmSsp. Further, PCR was carried out in the same manner as in Example 2 using two synthetic DNA primers designated RM-1 (having the sequence 5′-ATCATATGATGCACCGACAAGCT-3′) and RM-6R (having the sequence 5′-ACAATATTGTATTGAGGGCATTCGGGCGACTGC-3′) for amplifying a fragment, about 100 bp in size, resulting from deletion of the N portion. The fragment was cleaved with the restriction enzymes NdeI and SspI, and the resulting fragment was recombined to the major fragment of pNTRmSsp as resulting from digestion with the restriction enzymes NdeI and SspI to construct pNTRm6.

EXAMPLE 8

[0095] The thus-constructed decaprenyl diphosphate synthase gene expression vector pNTRm6 was introduced into Escherichia coli HB101, the microorganisms were shake-cultured overnight in 10 mL of LB medium at 37° C., and cells were harvested by centrifugation (3,000 revolutions, 20 minutes).

[0096] The cells were suspended in 1 mL of a 3% aqueous solution of sulfuric acid and, after 30 minutes of heat treatment at 120° C., 2 mL of a 14% aqueous solution of sodium hydroxide was added, followed by further 15 minutes of heat treatment at 120° C. To the thus-treated suspension was added 3 mL of hexane-isopropanol (10:2) for effecting extraction. After centrifugation, 1.5 mL of the organic solvent layer was separated, and the solvent was evaporated to dryness under reduced pressure conditions. The residue was dissolved in 200 μl of ethanol, and 20 μl of the solution was analyzed by high-performance liquid chromatography (using LC-10A, product of Shimadzu Corp.). For separation, a reversed phase column (YMC-pack ODS-A, 250×4.6 mm, S-5 μm, 120A) was used, together with ethanol-methanol (2:1) as the mobile phase solvent. The coenzyme Q₁₀ formed was detected based on the absorbance at the wavelength 275 nm. The results are shown in FIG. 3. As shown in FIG. 3, it was revealed that, upon introduction of the decaprenyl diphosphate synthase gene for expression thereof, coenzyme Q₁₀, which is originally not produced in Escherichia coli, could now be produced in the transformant and that conversion could be attained so as to attain coenzyme Q₁₀ production in significantly larger amounts as compared with the Escherichia coli strain transformed with pNTRm2.

[0097] The thus-obtained recombinant Escherichia coli HB101(pNTRm6) has been deposited, under the Budapest Treaty, with the National Institute of Advanced Industrial Science and Technology International Patent Organism Depositary (Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki, Japan) as of Oct. 19, 2000 (deposition/accession No. FERM BP-7332).

EXAMPLE 9

[0098] For eliminating the mitochondrial transitional sequence characteristic of eukaryotes from the sequence under SEQ ID NO:1 in order to attain abundant expression in prokaryotes, PCR was carried out in the same manner as in Example 2 using two synthetic DNA primers designated RmNEco (having the sequence 5′-ACGAATTCGATGATCTTCGACCCACTCCAACT-3′) and Rm-CE2 (having the sequence 5′-AAGAATTCCTACTTTGTTCGGTTGAGCACAG-3′), with pNTRm2 as the template. The thus-amplified 1.2 kbp fragment was cleaved with the restriction enzymes BamHI and EcoRI, and the thus prepared fragment was joined to the major fragment of pUC18 as obtained by digestion with the restriction enzymes BamHI and EcoRI to construct pUCRm3.

EXAMPLE 10

[0099] The thus-constructed decaprenyl diphosphate synthase gene expression vector pUCRm3 was introduced into Escherichia coli DH5α, the microorganisms were shake-cultured overnight in 10 mL of LB medium at 37° C., and cells were harvested by centrifugation (3,000 revolutions, 20 minutes).

[0100] The cells were suspended in 1 mL of a 3% aqueous solution of sulfuric acid and, after 30 minutes of heat treatment at 120° C., 2 mL of a 14% aqueous solution of sodium hydroxide was added, followed by further 15 minutes of heat treatment at 120° C. To the thus-treated suspension was added 3 mL of hexane-isopropanol (10:2) for effecting extraction. After centrifugation, 1.5 mL of the organic solvent layer was separated, and the solvent was evaporated to dryness under reduced pressure conditions. The residue was dissolved in 200 μl of ethanol, and 20 μl of the solution was analyzed by high-performance liquid chromatography (using LC-10A, product of Shimadzu Corp.). For separation, a reversed phase column (YMC-pack ODS-A, 250×4.6 mm, S-5 μm, 120A) was used, together with ethanol-methanol (2:1) as the mobile phase solvent. The coenzyme Q₁₀ formed was detected based on the absorbance at the wavelength 275 nm. The results are shown in FIG. 3. As shown in FIG. 5, it was revealed that, upon introduction of the decaprenyl diphosphate synthase gene for expression thereof, coenzyme Q₁₀, which is originally not produced in Escherichia coli, could now be produced in the transformant and that conversion could be attained so as to attain coenzyme Q₁₀ production in significantly larger amounts as compared with the Escherichia coli strains transformed with pNTRm2 and pNTRm6, respectively.

[0101] The thus-obtained recombinant Escherichia coli DH5α (pUCRm3) has been deposited, under the Budapest Treaty, with the National Institute of Advanced Industrial Science and Technology International Patent Organism Depositary (Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki, Japan) as of Jun. 22, 2001 (deposition/accession No. FERM BP-7638).

Industrial Applicability

[0102] A gene encoding decaprenyl diphosphate synthase, which is the key enzyme in the biosynthesis of coenzyme Q₁₀, was isolated from a fungal species belonging to the genus Rhodotorula and it was sequenced. This could successfully be introduced in Escherichia coli for expression thereof. Furthermore, improvements in gene sequence successfully resulted in production of coenzyme Q₁₀ in significant amounts. By using the method of the invention, it becomes possible to efficiently produce coenzyme Q₁₀, which is in use as a drug, among others.

1 6 1 1614 DNA Rhodotorula minuta 1 atg atg cac cga caa gct gca tgt aga gtg tgc agt cac act tgc agt 48 MET MET His Arg Gln Ala Ala Cys Arg Val Cys Ser His Thr Cys Ser 1 5 10 15 cgc ccg aat gcc ctg ttg gcc ggc ata tat gga cca tca tca gca tca 96 Arg Pro Asn Ala Leu Leu Ala Gly Ile Tyr Gly Pro Ser Ser Ala Ser 20 25 30 tca tcg acg acg acg acg act tca aca tca aga agc aac cac aac aac 144 Ser Ser Thr Thr Thr Thr Thr Ser Thr Ser Arg Ser Asn His Asn Asn 35 40 45 agt gta cga ttc aag cat tcg ttg agt aat act agc aaa cca gct gcc 192 Ser Val Arg Phe Lys His Ser Leu Ser Asn Thr Ser Lys Pro Ala Ala 50 55 60 aga tcg aca tcc act tcc gct cct gct ctc tct ccc tct tct tca aca 240 Arg Ser Thr Ser Thr Ser Ala Pro Ala Leu Ser Pro Ser Ser Ser Thr 65 70 75 80 agc gat cct caa tct tcc tca tca cca tcc tct tcc tct tct tct tct 288 Ser Asp Pro Gln Ser Ser Ser Ser Pro Ser Ser Ser Ser Ser Ser Ser 85 90 95 tct att ctt cct gac ttt ttg aga tca cca tta tcg tcc tcg tcc tcc 336 Ser Ile Leu Pro Asp Phe Leu Arg Ser Pro Leu Ser Ser Ser Ser Ser 100 105 110 tca tcc tcg aca agt agc tct tca tca tca tcg tca agc aat cgc tcc 384 Ser Ser Ser Thr Ser Ser Ser Ser Ser Ser Ser Ser Ser Asn Arg Ser 115 120 125 aaa aac act aac agc aat aca atc ttc gac cca ctc caa ctc gta ggc 432 Lys Asn Thr Asn Ser Asn Thr Ile Phe Asp Pro Leu Gln Leu Val Gly 130 135 140 aat gaa ctg tca agt ctc cgg tca aac gtc caa gcc cta ctg gga tca 480 Asn Glu Leu Ser Ser Leu Arg Ser Asn Val Gln Ala Leu Leu Gly Ser 145 150 155 160 ggt cat ccc gcc cta gac acg ata gca aag tac tac ttc caa gcg gag 528 Gly His Pro Ala Leu Asp Thr Ile Ala Lys Tyr Tyr Phe Gln Ala Glu 165 170 175 ggc aaa cat att cgg cct atg atc gtt ctt ctc atg tcc caa gcc aca 576 Gly Lys His Ile Arg Pro MET Ile Val Leu Leu MET Ser Gln Ala Thr 180 185 190 aac ggt cta gcg ccc ggg ttt gaa gaa cgc tca aaa ttg gaa cta tca 624 Asn Gly Leu Ala Pro Gly Phe Glu Glu Arg Ser Lys Leu Glu Leu Ser 195 200 205 ggt cgg aaa cag act gat ccc tcc agg tca atc aat gat cct ctc gaa 672 Gly Arg Lys Gln Thr Asp Pro Ser Arg Ser Ile Asn Asp Pro Leu Glu 210 215 220 gtg aaa gca gat gag ata ctc aac gat tcg aat ccc tct tcg ttc gct 720 Val Lys Ala Asp Glu Ile Leu Asn Asp Ser Asn Pro Ser Ser Phe Ala 225 230 235 240 gcg agc tcc tct tcg ccg ctc gat agc atg ccg tcc acg tcg aat gtc 768 Ala Ser Ser Ser Ser Pro Leu Asp Ser MET Pro Ser Thr Ser Asn Val 245 250 255 cta ccc tcg caa cga cgc ctc gcg gaa atc acc gaa atg atc cac gta 816 Leu Pro Ser Gln Arg Arg Leu Ala Glu Ile Thr Glu MET Ile His Val 260 265 270 gct tcg cta ttg cac gac gat gtc ata gac ggt tca gcc atg agg aga 864 Ala Ser Leu Leu His Asp Asp Val Ile Asp Gly Ser Ala MET Arg Arg 275 280 285 gca caa gcg tcc gcc ccc gct gca ttc ggg aac aag atc tcg gtg ctg 912 Ala Gln Ala Ser Ala Pro Ala Ala Phe Gly Asn Lys Ile Ser Val Leu 290 295 300 ggc ggg gat ttc ctc ctc gct cgt gct tcg ctg tac ctc tcc cga cta 960 Gly Gly Asp Phe Leu Leu Ala Arg Ala Ser Leu Tyr Leu Ser Arg Leu 305 310 315 320 ggg agc aac gag gtc gtc gag cta gta gcc tcc gtg cta gct aat cta 1008 Gly Ser Asn Glu Val Val Glu Leu Val Ala Ser Val Leu Ala Asn Leu 325 330 335 gta gag ggc gaa gtc atg cag atc aag gga aat gct cct gaa agc aat 1056 Val Glu Gly Glu Val MET Gln Ile Lys Gly Asn Ala Pro Glu Ser Asn 340 345 350 gca agc gga agc aaa gag gta gca gtg cac aga ttg acc ccg gaa att 1104 Ala Ser Gly Ser Lys Glu Val Ala Val His Arg Leu Thr Pro Glu Ile 355 360 365 ttc gaa cat tat atg aag aag aca tac ttg aag acc gca agt ctc atc 1152 Phe Glu His Tyr MET Lys Lys Thr Tyr Leu Lys Thr Ala Ser Leu Ile 370 375 380 gcg aaa tcg aca aga gcg acc act atc ctc ggt gga gca ggc gag aaa 1200 Ala Lys Ser Thr Arg Ala Thr Thr Ile Leu Gly Gly Ala Gly Glu Lys 385 390 395 400 cag ggg tgg ata gag ggc gag cgc ata aaa gac att gcg tac tcg tac 1248 Gln Gly Trp Ile Glu Gly Glu Arg Ile Lys Asp Ile Ala Tyr Ser Tyr 405 410 415 ggt cgc aat cta ggt att gct ttc cag ctc gtc gac gat cta cta gat 1296 Gly Arg Asn Leu Gly Ile Ala Phe Gln Leu Val Asp Asp Leu Leu Asp 420 425 430 ttc aca gct aca gac gcg caa ttc ggc aag ccc tca cag ggt gca gat 1344 Phe Thr Ala Thr Asp Ala Gln Phe Gly Lys Pro Ser Gln Gly Ala Asp 435 440 445 ctg aag ctc ggt ctc gca act gcg ccc gcg ctg tac gca tgg gaa gag 1392 Leu Lys Leu Gly Leu Ala Thr Ala Pro Ala Leu Tyr Ala Trp Glu Glu 450 455 460 ttc ccg gag atg ggc cag atg att ctc cgc aag ttt gag aac gaa ggc 1440 Phe Pro Glu MET Gly Gln MET Ile Leu Arg Lys Phe Glu Asn Glu Gly 465 470 475 480 gat gtc gaa act gcc agg aat cta gta aga aag tca gct gga ccg gaa 1488 Asp Val Glu Thr Ala Arg Asn Leu Val Arg Lys Ser Ala Gly Pro Glu 485 490 495 aag acc gtg aaa ttg gcg gaa aaa cat gcc gca ctc gca atg gag gcc 1536 Lys Thr Val Lys Leu Ala Glu Lys His Ala Ala Leu Ala MET Glu Ala 500 505 510 ctg cag gga ttg ccg gag tcg gac gct aga gaa gcg ctc gaa ggc ctg 1584 Leu Gln Gly Leu Pro Glu Ser Asp Ala Arg Glu Ala Leu Glu Gly Leu 515 520 525 acc aag act gtg ctc aac cga aca aag tag 1614 Thr Lys Thr Val Leu Asn Arg Thr Lys 530 535 2 537 PRT Rhodotorula minuta 2 MET MET His Arg Gln Ala Ala Cys Arg Val Cys Ser His Thr Cys 1 5 10 15 Ser Arg Pro Asn Ala Leu Leu Ala Gly Ile Tyr Gly Pro Ser Ser 20 25 30 Ala Ser Ser Ser Thr Thr Thr Thr Thr Ser Thr Ser Arg Ser Asn 35 40 45 His Asn Asn Ser Val Arg Phe Lys His Ser Leu Ser Asn Thr Ser 50 55 60 Lys Pro Ala Ala Arg Ser Thr Ser Thr Ser Ala Pro Ala Leu Ser 65 70 75 Pro Ser Ser Ser Thr Ser Asp Pro Gln Ser Ser Ser Ser Pro Ser 80 85 90 Ser Ser Ser Ser Ser Ser Ser Ile Leu Pro Asp Phe Leu Arg Ser 95 100 105 Pro Leu Ser Ser Ser Ser Ser Ser Ser Ser Thr Ser Ser Ser Ser 110 115 120 Ser Ser Ser Ser Ser Asn Arg Ser Lys Asn Thr Asn Ser Asn Thr 125 130 135 Ile Phe Asp Pro Leu Gln Leu Val Gly Asn Glu Leu Ser Ser Leu 140 145 150 Arg Ser Asn Val Gln Ala Leu Leu Gly Ser Gly His Pro Ala Leu 155 160 165 Asp Thr Ile Ala Lys Tyr Tyr Phe Gln Ala Glu Gly Lys His Ile 170 175 180 Arg Pro MET Ile Val Leu Leu MET Ser Gln Ala Thr Asn Gly Leu 185 190 195 Ala Pro Gly Phe Glu Glu Arg Ser Lys Leu Glu Leu Ser Gly Arg 200 205 210 Lys Gln Thr Asp Pro Ser Arg Ser Ile Asn Asp Pro Leu Glu Val 215 220 225 Lys Ala Asp Glu Ile Leu Asn Asp Ser Asn Pro Ser Ser Phe Ala 230 235 240 Ala Ser Ser Ser Ser Pro Leu Asp Ser MET Pro Ser Thr Ser Asn 245 250 255 Val Leu Pro Ser Gln Arg Arg Leu Ala Glu Ile Thr Glu MET Ile 260 265 270 His Val Ala Ser Leu Leu His Asp Asp Val Ile Asp Gly Ser Ala 275 280 285 MET Arg Arg Ala Gln Ala Ser Ala Pro Ala Ala Phe Gly Asn Lys 290 295 300 Ile Ser Val Leu Gly Gly Asp Phe Leu Leu Ala Arg Ala Ser Leu 305 310 315 Tyr Leu Ser Arg Leu Gly Ser Asn Glu Val Val Glu Leu Val Ala 320 325 330 Ser Val Leu Ala Asn Leu Val Glu Gly Glu Val MET Gln Ile Lys 335 340 345 Gly Asn Ala Pro Glu Ser Asn Ala Ser Gly Ser Lys Glu Val Ala 350 355 360 Val His Arg Leu Thr Pro Glu Ile Phe Glu His Tyr MET Lys Lys 365 370 375 Thr Tyr Leu Lys Thr Ala Ser Leu Ile Ala Lys Ser Thr Arg Ala 380 385 390 Thr Thr Ile Leu Gly Gly Ala Gly Glu Lys Gln Gly Trp Ile Glu 395 400 405 Gly Glu Arg Ile Lys Asp Ile Ala Tyr Ser Tyr Gly Arg Asn Leu 410 415 420 Gly Ile Ala Phe Gln Leu Val Asp Asp Leu Leu Asp Phe Thr Ala 425 430 435 Thr Asp Ala Gln Phe Gly Lys Pro Ser Gln Gly Ala Asp Leu Lys 440 445 450 Leu Gly Leu Ala Thr Ala Pro Ala Leu Tyr Ala Trp Glu Glu Phe 455 460 465 Pro Glu MET Gly Gln MET Ile Leu Arg Lys Phe Glu Asn Glu Gly 470 475 480 Asp Val Glu Thr Ala Arg Asn Leu Val Arg Lys Ser Ala Gly Pro 485 490 495 Glu Lys Thr Val Lys Leu Ala Glu Lys His Ala Ala Leu Ala MET 500 505 510 Glu Ala Leu Gln Gly Leu Pro Glu Ser Asp Ala Arg Glu Ala Leu 515 520 525 Glu Gly Leu Thr Lys Thr Val Leu Asn Arg Thr Lys 530 535 3 1278 DNA Rhodotorula minuta 3 atg atg cac cga caa gct gca tgt aga gtg tgc agt cac act tgc agt 48 MET MET His Arg Gln Ala Ala Cys Arg Val Cys Ser His Thr Cys Ser 1 5 10 15 cgc ccg aat gcc ctc aat aca atc ttc gac cca ctc caa ctc gta ggc 96 Arg Pro Asn Ala Leu Asn Thr Ile Phe Asp Pro Leu Gln Leu Val Gly 20 25 30 aat gaa ctg tca agt ctc cgg tca aac gtc caa gcc cta ctg gga tca 144 Asn Glu Leu Ser Ser Leu Arg Ser Asn Val Gln Ala Leu Leu Gly Ser 35 40 45 ggt cat ccc gcc cta gac acg ata gca aag tac tac ttc caa gcg gag 192 Gly His Pro Ala Leu Asp Thr Ile Ala Lys Tyr Tyr Phe Gln Ala Glu 50 55 60 ggc aaa cat att cgg cct atg atc gtt ctt ctc atg tcc caa gcc aca 240 Gly Lys His Ile Arg Pro MET Ile Val Leu Leu MET Ser Gln Ala Thr 65 70 75 80 aac ggt cta gcg ccc ggg ttt gaa gaa cgc tca aaa ttg gaa cta tca 288 Asn Gly Leu Ala Pro Gly Phe Glu Glu Arg Ser Lys Leu Glu Leu Ser 85 90 95 ggt cgg aaa cag act gat ccc tcc agg tca atc aat gat cct ctc gaa 336 Gly Arg Lys Gln Thr Asp Pro Ser Arg Ser Ile Asn Asp Pro Leu Glu 100 105 110 gtg aaa gca gat gag ata ctc aac gat tcg aat ccc tct tcg ttc gct 384 Val Lys Ala Asp Glu Ile Leu Asn Asp Ser Asn Pro Ser Ser Phe Ala 115 120 125 gcg agc tcc tct tcg ccg ctc gat agc atg ccg tcc acg tcg aat gtc 432 Ala Ser Ser Ser Ser Pro Leu Asp Ser MET Pro Ser Thr Ser Asn Val 130 135 140 cta ccc tcg caa cga cgc ctc gcg gaa atc acc gaa atg atc cac gta 480 Leu Pro Ser Gln Arg Arg Leu Ala Glu Ile Thr Glu MET Ile His Val 145 150 155 160 gct tcg cta ttg cac gac gat gtc ata gac ggt tca gcc atg agg aga 528 Ala Ser Leu Leu His Asp Asp Val Ile Asp Gly Ser Ala MET Arg Arg 165 170 175 gca caa gcg tcc gcc ccc gct gca ttc ggg aac aag atc tcg gtg ctg 576 Ala Gln Ala Ser Ala Pro Ala Ala Phe Gly Asn Lys Ile Ser Val Leu 180 185 190 ggc ggg gat ttc ctc ctc gct cgt gct tcg ctg tac ctc tcc cga cta 624 Gly Gly Asp Phe Leu Leu Ala Arg Ala Ser Leu Tyr Leu Ser Arg Leu 195 200 205 ggg agc aac gag gtc gtc gag cta gta gcc tcc gtg cta gct aat cta 672 Gly Ser Asn Glu Val Val Glu Leu Val Ala Ser Val Leu Ala Asn Leu 210 215 220 gta gag ggc gaa gtc atg cag atc aag gga aat gct cct gaa agc aat 720 Val Glu Gly Glu Val MET Gln Ile Lys Gly Asn Ala Pro Glu Ser Asn 225 230 235 240 gca agc gga agc aaa gag gta gca gtg cac aga ttg acc ccg gaa att 768 Ala Ser Gly Ser Lys Glu Val Ala Val His Arg Leu Thr Pro Glu Ile 245 250 255 ttc gaa cat tat atg aag aag aca tac ttg aag acc gca agt ctc atc 816 Phe Glu His Tyr MET Lys Lys Thr Tyr Leu Lys Thr Ala Ser Leu Ile 260 265 270 gcg aaa tcg aca aga gcg acc act atc ctc ggt gga gca ggc gag aaa 864 Ala Lys Ser Thr Arg Ala Thr Thr Ile Leu Gly Gly Ala Gly Glu Lys 275 280 285 cag ggg tgg ata gag ggc gag cgc ata aaa gac att gcg tac tcg tac 912 Gln Gly Trp Ile Glu Gly Glu Arg Ile Lys Asp Ile Ala Tyr Ser Tyr 290 295 300 ggt cgc aat cta ggt att gct ttc cag ctc gtc gac gat cta cta gat 960 Gly Arg Asn Leu Gly Ile Ala Phe Gln Leu Val Asp Asp Leu Leu Asp 305 310 315 320 ttc aca gct aca gac gcg caa ttc ggc aag ccc tca cag ggt gca gat 1008 Phe Thr Ala Thr Asp Ala Gln Phe Gly Lys Pro Ser Gln Gly Ala Asp 325 330 335 ctg aag ctc ggt ctc gca act gcg ccc gcg ctg tac gca tgg gaa gag 1056 Leu Lys Leu Gly Leu Ala Thr Ala Pro Ala Leu Tyr Ala Trp Glu Glu 340 345 350 ttc ccg gag atg ggc cag atg att ctc cgc aag ttt gag aac gaa ggc 1104 Phe Pro Glu MET Gly Gln MET Ile Leu Arg Lys Phe Glu Asn Glu Gly 355 360 365 gat gtc gaa act gcc agg aat cta gta aga aag tca gct gga ccg gaa 1152 Asp Val Glu Thr Ala Arg Asn Leu Val Arg Lys Ser Ala Gly Pro Glu 370 375 380 aag acc gtg aaa ttg gcg gaa aaa cat gcc gca ctc gca atg gag gcc 1200 Lys Thr Val Lys Leu Ala Glu Lys His Ala Ala Leu Ala MET Glu Ala 385 390 395 400 ctg cag gga ttg ccg gag tcg gac gct aga gaa gcg ctc gaa ggc ctg 1248 Leu Gln Gly Leu Pro Glu Ser Asp Ala Arg Glu Ala Leu Glu Gly Leu 405 410 415 acc aag act gtg ctc aac cga aca aag tag 1278 Thr Lys Thr Val Leu Asn Arg Thr Lys 420 425 4 425 PRT Rhodotorula 4 MET MET His Arg Gln Ala Ala Cys Arg Val Cys Ser His Thr Cys 1 5 10 15 Ser Arg Pro Asn Ala Leu Asn Thr Ile Phe Asp Pro Leu Gln Leu 20 25 30 Val Gly Asn Glu Leu Ser Ser Leu Arg Ser Asn Val Gln Ala Leu 35 40 45 Leu Gly Ser Gly His Pro Ala Leu Asp Thr Ile Ala Lys Tyr Tyr 50 55 60 Phe Gln Ala Glu Gly Lys His Ile Arg Pro MET Ile Val Leu Leu 65 70 75 MET Ser Gln Ala Thr Asn Gly Leu Ala Pro Gly Phe Glu Glu Arg 80 85 90 Ser Lys Leu Glu Leu Ser Gly Arg Lys Gln Thr Asp Pro Ser Arg 95 100 105 Ser Ile Asn Asp Pro Leu Glu Val Lys Ala Asp Glu Ile Leu Asn 110 115 120 Asp Ser Asn Pro Ser Ser Phe Ala Ala Ser Ser Ser Ser Pro Leu 125 130 135 Asp Ser MET Pro Ser Thr Ser Asn Val Leu Pro Ser Gln Arg Arg 140 145 150 Leu Ala Glu Ile Thr Glu MET Ile His Val Ala Ser Leu Leu His 155 160 165 Asp Asp Val Ile Asp Gly Ser Ala MET Arg Arg Ala Gln Ala Ser 170 175 180 Ala Pro Ala Ala Phe Gly Asn Lys Ile Ser Val Leu Gly Gly Asp 185 190 195 Phe Leu Leu Ala Arg Ala Ser Leu Tyr Leu Ser Arg Leu Gly Ser 200 205 210 Asn Glu Val Val Glu Leu Val Ala Ser Val Leu Ala Asn Leu Val 215 220 225 Glu Gly Glu Val MET Gln Ile Lys Gly Asn Ala Pro Glu Ser Asn 230 235 240 Ala Ser Gly Ser Lys Glu Val Ala Val His Arg Leu Thr Pro Glu 245 250 255 Ile Phe Glu His Tyr MET Lys Lys Thr Tyr Leu Lys Thr Ala Ser 260 265 270 Leu Ile Ala Lys Ser Thr Arg Ala Thr Thr Ile Leu Gly Gly Ala 275 280 285 Gly Glu Lys Gln Gly Trp Ile Glu Gly Glu Arg Ile Lys Asp Ile 290 295 300 Ala Tyr Ser Tyr Gly Arg Asn Leu Gly Ile Ala Phe Gln Leu Val 305 310 315 Asp Asp Leu Leu Asp Phe Thr Ala Thr Asp Ala Gln Phe Gly Lys 320 325 330 Pro Ser Gln Gly Ala Asp Leu Lys Leu Gly Leu Ala Thr Ala Pro 335 340 345 Ala Leu Tyr Ala Trp Glu Glu Phe Pro Glu MET Gly Gln MET Ile 350 355 360 Leu Arg Lys Phe Glu Asn Glu Gly Asp Val Glu Thr Ala Arg Asn 365 370 375 Leu Val Arg Lys Ser Ala Gly Pro Glu Lys Thr Val Lys Leu Ala 380 385 390 Glu Lys His Ala Ala Leu Ala MET Glu Ala Leu Gln Gly Leu Pro 395 400 405 Glu Ser Asp Ala Arg Glu Ala Leu Glu Gly Leu Thr Lys Thr Val 410 415 420 Leu Asn Arg Thr Lys 425 5 1212 DNA Rhodotorula minuta 5 atg atc ttc gac cca ctc caa ctc gta ggc aat gaa ctg tca agt ctc 48 Met Ile Phe Asp Pro Leu Gln Leu Val Gly Asn Glu Leu Ser Ser Leu 1 5 10 15 cgg tca aac gtc caa gcc cta ctg gga tca ggt cat ccc gcc cta gac 96 Arg Ser Asn Val Gln Ala Leu Leu Gly Ser Gly His Pro Ala Leu Asp 20 25 30 acg ata gca aag tac tac ttc caa gcg gag ggc aaa cat att cgg cct 144 Thr Ile Ala Lys Tyr Tyr Phe Gln Ala Glu Gly Lys His Ile Arg Pro 35 40 45 atg atc gtt ctt ctc atg tcc caa gcc aca aac ggt cta gcg ccc ggg 192 Met Ile Val Leu Leu Met Ser Gln Ala Thr Asn Gly Leu Ala Pro Gly 50 55 60 ttt gaa gaa cgc tca aaa ttg gaa cta tca ggt cgg aaa cag act gat 240 Phe Glu Glu Arg Ser Lys Leu Glu Leu Ser Gly Arg Lys Gln Thr Asp 65 70 75 80 ccc tcc agg tca atc aat gat cct ctc gaa gtg aaa gca gat gag ata 288 Pro Ser Arg Ser Ile Asn Asp Pro Leu Glu Val Lys Ala Asp Glu Ile 85 90 95 ctc aac gat tcg aat ccc tct tcg ttc gct gcg agc tcc tct tcg ccg 336 Leu Asn Asp Ser Asn Pro Ser Ser Phe Ala Ala Ser Ser Ser Ser Pro 100 105 110 ctc gat agc atg ccg tcc acg tcg aat gtc cta ccc tcg caa cga cgc 384 Leu Asp Ser Met Pro Ser Thr Ser Asn Val Leu Pro Ser Gln Arg Arg 115 120 125 ctc gcg gaa atc acc gaa atg atc cac gta gct tcg cta ttg cac gac 432 Leu Ala Glu Ile Thr Glu Met Ile His Val Ala Ser Leu Leu His Asp 130 135 140 gat gtc ata gac ggt tca gcc atg agg aga gca caa gcg tcc gcc ccc 480 Asp Val Ile Asp Gly Ser Ala Met Arg Arg Ala Gln Ala Ser Ala Pro 145 150 155 160 gct gca ttc ggg aac aag atc tcg gtg ctg ggc ggg gat ttc ctc ctc 528 Ala Ala Phe Gly Asn Lys Ile Ser Val Leu Gly Gly Asp Phe Leu Leu 165 170 175 gct cgt gct tcg ctg tac ctc tcc cga cta ggg agc aac gag gtc gtc 576 Ala Arg Ala Ser Leu Tyr Leu Ser Arg Leu Gly Ser Asn Glu Val Val 180 185 190 gag cta gta gcc tcc gtg cta gct aat cta gta gag ggc gaa gtc atg 624 Glu Leu Val Ala Ser Val Leu Ala Asn Leu Val Glu Gly Glu Val Met 195 200 205 cag atc aag gga aat gct cct gaa agc aat gca agc gga agc aaa gag 672 Gln Ile Lys Gly Asn Ala Pro Glu Ser Asn Ala Ser Gly Ser Lys Glu 210 215 220 gta gca gtg cac aga ttg acc ccg gaa att ttc gaa cat tat atg aag 720 Val Ala Val His Arg Leu Thr Pro Glu Ile Phe Glu His Tyr Met Lys 225 230 235 240 aag aca tac ttg aag acc gca agt ctc atc gcg aaa tcg aca aga gcg 768 Lys Thr Tyr Leu Lys Thr Ala Ser Leu Ile Ala Lys Ser Thr Arg Ala 245 250 255 acc act atc ctc ggt gga gca ggc gag aaa cag ggg tgg ata gag ggc 816 Thr Thr Ile Leu Gly Gly Ala Gly Glu Lys Gln Gly Trp Ile Glu Gly 260 265 270 gag cgc ata aaa gac att gcg tac tcg tac ggt cgc aat cta ggt att 864 Glu Arg Ile Lys Asp Ile Ala Tyr Ser Tyr Gly Arg Asn Leu Gly Ile 275 280 285 gct ttc cag ctc gtc gac gat cta cta gat ttc aca gct aca gac gcg 912 Ala Phe Gln Leu Val Asp Asp Leu Leu Asp Phe Thr Ala Thr Asp Ala 290 295 300 caa ttc ggc aag ccc tca cag ggt gca gat ctg aag ctc ggt ctc gca 960 Gln Phe Gly Lys Pro Ser Gln Gly Ala Asp Leu Lys Leu Gly Leu Ala 305 310 315 320 act gcg ccc gcg ctg tac gca tgg gaa gag ttc ccg gag atg ggc cag 1008 Thr Ala Pro Ala Leu Tyr Ala Trp Glu Glu Phe Pro Glu Met Gly Gln 325 330 335 atg att ctc cgc aag ttt gag aac gaa ggc gat gtc gaa act gcc agg 1056 Met Ile Leu Arg Lys Phe Glu Asn Glu Gly Asp Val Glu Thr Ala Arg 340 345 350 aat cta gta aga aag tca gct gga ccg gaa aag acc gtg aaa ttg gcg 1104 Asn Leu Val Arg Lys Ser Ala Gly Pro Glu Lys Thr Val Lys Leu Ala 355 360 365 gaa aaa cat gcc gca ctc gca atg gag gcc ctg cag gga ttg ccg gag 1152 Glu Lys His Ala Ala Leu Ala Met Glu Ala Leu Gln Gly Leu Pro Glu 370 375 380 tcg gac gct aga gaa gcg ctc gaa ggc ctg acc aag act gtg ctc aac 1200 Ser Asp Ala Arg Glu Ala Leu Glu Gly Leu Thr Lys Thr Val Leu Asn 385 390 395 400 cga aca aag tag 1212 Arg Thr Lys 403 6 403 PRT Rhodotorula minuta 6 Met Ile Phe Asp Pro Leu Gln Leu Val Gly Asn Glu Leu Ser Ser 1 5 10 15 Leu Arg Ser Asn Val Gln Ala Leu Leu Gly Ser Gly His Pro Ala 20 25 30 Leu Asp Thr Ile Ala Lys Tyr Tyr Phe Gln Ala Glu Gly Lys His 35 40 45 Ile Arg Pro Met Ile Val Leu Leu Met Ser Gln Ala Thr Asn Gly 50 55 60 Leu Ala Pro Gly Phe Glu Glu Arg Ser Lys Leu Glu Leu Ser Gly 65 70 75 Arg Lys Gln Thr Asp Pro Ser Arg Ser Ile Asn Asp Pro Leu Glu 80 85 90 Val Lys Ala Asp Glu Ile Leu Asn Asp Ser Asn Pro Ser Ser Phe 95 100 105 Ala Ala Ser Ser Ser Ser Pro Leu Asp Ser Met Pro Ser Thr Ser 110 115 120 Asn Val Leu Pro Ser Gln Arg Arg Leu Ala Glu Ile Thr Glu Met 125 130 135 Ile His Val Ala Ser Leu Leu His Asp Asp Val Ile Asp Gly Ser 140 145 150 Ala Met Arg Arg Ala Gln Ala Ser Ala Pro Ala Ala Phe Gly Asn 155 160 165 Lys Ile Ser Val Leu Gly Gly Asp Phe Leu Leu Ala Arg Ala Ser 170 175 180 Leu Tyr Leu Ser Arg Leu Gly Ser Asn Glu Val Val Glu Leu Val 185 190 195 Ala Ser Val Leu Ala Asn Leu Val Glu Gly Glu Val Met Gln Ile 200 205 210 Lys Gly Asn Ala Pro Glu Ser Asn Ala Ser Gly Ser Lys Glu Val 215 220 225 Ala Val His Arg Leu Thr Pro Glu Ile Phe Glu His Tyr Met Lys 230 235 240 Lys Thr Tyr Leu Lys Thr Ala Ser Leu Ile Ala Lys Ser Thr Arg 245 250 255 Ala Thr Thr Ile Leu Gly Gly Ala Gly Glu Lys Gln Gly Trp Ile 260 265 270 Glu Gly Glu Arg Ile Lys Asp Ile Ala Tyr Ser Tyr Gly Arg Asn 275 280 285 Leu Gly Ile Ala Phe Gln Leu Val Asp Asp Leu Leu Asp Phe Thr 290 295 300 Ala Thr Asp Ala Gln Phe Gly Lys Pro Ser Gln Gly Ala Asp Leu 305 310 315 Lys Leu Gly Leu Ala Thr Ala Pro Ala Leu Tyr Ala Trp Glu Glu 320 325 330 Phe Pro Glu Met Gly Gln Met Ile Leu Arg Lys Phe Glu Asn Glu 335 340 345 Gly Asp Val Glu Thr Ala Arg Asn Leu Val Arg Lys Ser Ala Gly 350 355 360 Pro Glu Lys Thr Val Lys Leu Ala Glu Lys His Ala Ala Leu Ala 365 370 375 MET Glu Ala Leu Gln Gly Leu Pro Glu Ser Asp Ala Arg Glu Ala 380 385 390 Leu Glu Gly Leu Thr Lys Thr Val Leu Asn Arg Thr Lys 395 400 403 

1. A DNA of the following (a), (b) or (c): (a) a DNA whose base sequence is as described under SEQ ID NO:1; (b) a DNA having a DNA sequence derived from the base sequence shown under SEQ ID NO:1 by deletion, addition, insertion and/or substitution of one or several bases and encoding a protein having decaprenyl diphosphate synthase activity; (c) a DNA capable of hybridizing with a DNA comprising the base sequence shown under SEQ ID NO:1 under stringent conditions and encoding a protein having decaprenyl diphosphate synthase activity.
 2. A DNA of the following (d), (e) or (f): (d) a DNA whose base sequence is as described under SEQ ID NO:3; (e) a DNA having a DNA sequence derived from the base sequence shown under SEQ ID NO:3 by deletion, addition, insertion and/or substitution of one or several bases and encoding a protein having decaprenyl diphosphate synthase activity; (f) a DNA capable of hybridizing with a DNA comprising the base sequence shown under SEQ ID NO:3 under stringent conditions and encoding a protein having decaprenyl diphosphate synthase activity.
 3. A protein of the following (g) or (h): (g) a protein whose amino acid sequence is as described under SEQ ID NO:2; (h) a protein having an amino acid sequence derived from acid sequence shown under SEQ ID NO:2 by deletion, insertion and/or substitution of one or several amino acid residues and having decaprenyl diphosphate synthase activity.
 4. A protein of the following (i) or (j): (i) a protein whose amino acid sequence is as described under SEQ ID NO:4; (j) a protein having an amino acid sequence derived from the amino acid sequence shown under SEQ ID NO:4 by deletion, addition, insertion and/or substitution of one or several amino acid residues and having decaprenyl diphosphate synthase activity.
 5. A DNA encoding the protein according to claim
 3. 6. A DNA encoding the protein according to claim
 4. 7. An expression vector resulting from insertion of the DNA according to claim 1, 2, 5 or 6 into a vector for expression.
 8. The expression vector according to claim 7, wherein the vector for expression is pUCNT.
 9. The expression vector according to claim 8, which is pNTRm2.
 10. The expression vector according to claim 8, which is pNTRm6.
 11. A transformant resulting from transformation of a host microorganism with the DNA according to claim 1, 2, 5 or
 6. 12. A transformant resulting from transformation of a host microorganism with the expression vector according to claim 7, 8, 9 or
 10. 13. The transformant according to claim 11 or 12, wherein the host microorganism is a strain of Escherichia coli.
 14. The transformant according to claim 13, wherein the strain of Escherichia coli is Escherichia coli HB101.
 15. The transformant according to claim 14, which is E. coli HB101 (pNTRm2) (FERM BP-7333).
 16. The transformant according to claim 14, which is E. coli HB101 (pNTRm6) (FERM BP-7332).
 17. A process for producing coenzyme Q₁₀, which comprises cultivating the transformant according to claim 11, 12, 13, 14, 15 or 16 in a medium and recovering coenzyme Q₁₀ thus formed and accumulated in the medium.
 18. A DNA of the following (k), (l) or (m): (k) a DNA whose base sequence is as described under SEQ ID NO:5; (l) a DNA having a DNA sequence derived from the base sequence shown under SEQ ID NO:5 by deletion, addition, insertion and/or substitution of one or several bases and encoding a protein having decaprenyl diphosphate synthase activity; (m) a DNA capable of hybridizing with a DNA comprising the base sequence shown under SEQ ID NO:5 under stringent conditions and encoding a protein having decaprenyl diphosphate synthase activity.
 19. A protein of the following (n) or (o): (n) a protein whose amino acid sequence is as described under SEQ ID NO:6; (o) a protein having an amino acid sequence derived from the amino acid sequence shown under SEQ ID NO:6 by deletion, addition, insertion and/or substitution of one or several amino acid residues and having decaprenyl diphosphate synthase activity.
 20. A DNA encoding the protein according to claim
 19. 21. An expression vector resulting from insertion of the DNA according to claim 18 or 20 into a vector for expression.
 22. The expression vector according to claim 21, wherein the vector for expression is pUC18.
 23. The expression vector according to claim 22, which is pUCRm3.
 24. A transformant resulting from transformation of a host microorganism with the DNA according to claim 18 or
 20. 25. A transformant resulting from transformation of a host microorganism with the expression vector according to claim 21, 22 or
 23. 26. The transformant according to claim 24 or 25, wherein the host microorganism is a strain of Escherichia coli.
 27. The transformant according to claim 26, wherein the strain of Escherichia coli is Escherichia coli DH5α.
 28. The transformant according to claim 27, which is E. coli DH5α (pUCRm3) (FERM BP-7638).
 29. A process for producing coenzyme Q₁₀, which comprises cultivating the transformant according to claim 24, 25, 26, 27 or 28 in a medium and recovering coenzyme Q₁₀ thus formed and accumulated in the medium. 